Ecuacion de 2do grado
package Repaso;
import java.awt.GridLayout;
import javax.swing.*;
@SuppressWarnings("serial")
public class Ecuacion extends JFrame {
Double A;
Double B;
Double C;
JLabel lblA, lblB, lblC, lblx1, lblx2, lblvA, lblvB, lblvC, lblvDet;
JTextField txtA, txtB, txtC;
JButton btnAceptar, btnCancelar;
public Ecuacion() {
setTitle("Solucion");
setSize(250,200);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
dibujarInterfaz(); }
public void dibujarInterfaz() {
getContentPane().setLayout(new GridLayout(7,2));
lblA = new JLabel("Valor de A");
getContentPane().add(lblA);
txtA = new JTextField();
getContentPane().add(txtA);
lblB = new JLabel("Valor de B");
getContentPane().add(lblB);
txtB = new JTextField();
getContentPane().add(txtB);
lblC = new JLabel("Valor de C");
getContentPane().add(lblC);
txtC = new JTextField();
getContentPane().add(txtC);
lblx1 = new JLabel("X1 = ");
getContentPane().add(lblx1);
lblx2 = new JLabel("X2 = ");
getContentPane().add(lblx2);
lblvA = new JLabel("vA");
getContentPane().add(lblvA);
lblvB = new JLabel("vB");
getContentPane().add(lblvB);
lblvC = new JLabel("vC");
getContentPane().add(lblvC);
lblvDet = new JLabel("vDet");
getContentPane().add(lblvDet);
btnAceptar = new JButton("Resolver");
getContentPane().add(btnAceptar);
btnCancelar = new JButton("Cancelar");
getContentPane().add(btnCancelar);
btnCancelar.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evento){
System.exit(0);
}
} );
btnAceptar.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evento) {
String msj = " ";
if(txtA.getText().isEmpty()) {
msj += "Falta el valor de A\n";
}
if (txtB.getText().isEmpty()) {
msj += "Falta el valor de B\n";
}
if (txtC.getText().isEmpty()) {
msj += "Falta el valor de C\n";
}
A = Double.parseDouble(txtA.getText());
B = Double.parseDouble(txtB.getText());
C = Double.parseDouble(txtC.getText());
lblvA.setText("A = " + txtA.getText());
lblvB.setText("B = " + txtB.getText());
lblvC.setText("C = " + txtC.getText());
lblvDet.setText("Det = " + determinante());
if (msj.isEmpty()) {
A = Double.parseDouble(txtA.getText());
B = Double.parseDouble(txtB.getText());
C = Double.parseDouble(txtC.getText());
Double miSol[] = Solucion();
if ( miSol[0] == 100.0) {
lblx1.setText("Sin solucion");
lblx2.setText("Sin solucion");
}
else {
lblx1.setText("X1 = " + miSol[0].toString());
lblx2.setText("X2 = " + miSol[1].toString());
}
}
else {
javax.swing.JOptionPane.showMessageDialog(null, msj);
}
}
});
}
public Double determinante() {
return (B*B-4*A*C);
}
public Double[] Solucion() {
Double Sol[] = new Double[2];
if (determinante() == 0) {
Sol[0] = -B/2*A;
Sol[1] = Sol[0];
}
if (determinante() > 0) {
Sol[0] = (-B + Math.sqrt(determinante()));
Sol[0] = Sol[0]/(2*A);
Sol[1] = (-B + Math.sqrt(determinante()));
Sol[1] = Sol[1]/(2*A);
}
if (determinante() < 0) {
Sol[0] = 100.0;
Sol[1] = Sol[0];
}
return Sol;
}
public static void main(String args []) {
new Ecuacion().setVisible(true);
}
}
.jpg)